Generally, liquid crystals in liquid crystal display panels do not emit light themselves. Thus, liquid crystal display devices take in sunlight and the like as external light, and utilize that external light to display various images on the liquid crystal display panels. Thus, assuming cases where external light cannot be taken in, the liquid crystal display devices desirably have an irradiation device (a backlight unit) that irradiates the liquid crystals.
Such backlight units are available in various types. For example, as shown in FIG. 6, there is a direct-lit-type backlight unit 182 in which a plurality of fluorescent tubes 171 are arranged in parallel in a manner facing the back face of a liquid crystal display panel (see Patent Document 1).
In such a backlight unit 182, however, the fluorescent tubes 171 have their opposite ends held by lamp holders hd, and have parts of the fluorescent tubes 171 other than their opposite ends held by lamp clips 1c. The fluorescent tubes 171 emit light by an AC signal of several tens of KHz that is fed from an unillustrated inverter. The brightness of the fluorescent tubes 171 emitting light is controlled by an AC signal of 100 to 500 Hz, which is called a light control signal. Patent Document 1: JP-A-2006-32358 (see FIG. 1)